Apparatus for producing printed wiring by metal vaporization



Aug. 9, 1960 G. P. M sRAw, JR F APPARATUS FOR PRODUCING PRINTED WIRINGBY METAL VAPARIZATION Filed Dec. 7. 1956 .w we 4, fifi 5 WW w x /Z NM Mll c u o F. E 6 2 m WL% 0: Q H H n u 7 4 H m/ w m a 2 3 a M W m P, I M 0.f/ HHW i w 0 r m h H .H W m Ollll m 2 M a Y U m U. -H m f v 7 o fi H:Ha 6 3 3 2 b r-l George P. McGraw, Jr., Downers Grove, Ill., assignor toWestern Electric Company, Incorporated, New York, N.Y., a corporation ofNew York Filed Dec 7, 1956, S91. No. 626,897

. 4 Claims. (Cl. 118-49) This invention relates to printed wiring andmore par ticularly to apparatus for rapidly producing printed wiring forelectrical apparatus. 7

It is an object of the present invention to provide apparatus forrapidly producing printed wiring. 7

Another object is to provide apparatus for economically andexpeditiously producing such products by metal vaporization. Y

The objects may be achieved by utilizing an apparatus which may includemeans for continuously advancing a web of insulating material in a pathwhich engages the web with and causes rotation of a continuously movingpattern-defining element. Vaporized metal is directed through thepattern-defining element by a metal vaporizer. The vaporizer, webadvancing means and pattern-defining element are all enclosed in anevacuated chamber, whereby when the vaporized metal is directed throughthe pattern-defining element a pattern of metal will be applied to theweb which conforms to the pattern of said element.

A clear understanding of the invent-ion may be had by reference to thefollowingdetailed description, when considered with the accompanyingdrawing, in which:

Fig. 1 is an elevational view of an evacuated chamber with the frontwall thereof removed; 7 a p a Fig. 2 is an enlarged, fragmentary,transverse sectional view taken along the line 2-2 of Fig. 1 in thedirection of the arrows, showing the details of the pattern-definingelement, and

Fig. 3 is a fragmentary view of a web on which metal has been depositedin a pattern conforming to the pattern of the pattern-defining element.6

Referring now to 'the drawing wherein like reference charactersdesignate the same parts throughout the several views, there isillustrated an evacuated chamber 6, in which there is mounted an arbor 7for supporting a supply 8 of insulating material in web form. The web ofinsulating material 10 withdrawn from the supply 8 passes under a guideroller 9 and then over a pattern-defining element, designated generallyby the numeral 11. After passing over the pattern-defining element 11,the web passes under a guide roller 12, over guide rollers 13 and 14,under a guide roller 15 and thence to take up arbor 16. A vaporizer,designated generally by the numeral 17, is located adjacent to thetraveling web 10 at a point between the guide rollers 13 and 14, and issupplied with heating current throughcable 18 connected to a powersource (not shown). The arbors 7 and 16, guide rollers 9, 12, 13, 14 and15, and vaporizer 17 are mounted'on a back wall 31 of the chamber 6. Thearbor 16 is driven and the arbor 7 is retarded by suitable mechanisms(not shown) to advance the web 10 under tension.

The pattern-defining element 11 comprises a drum 22 having an outer endwall 23 permanently attached to a cylindrical wall24. The cylindricalWall 24 has a series of cut outs '25therethrough, which may be of anyde, sired configuration to define a pattern. The outer end States P tPatented Aug. 9, 1960 2 wall 23 is sealed to the cylindrical wall 24,to, in eflfect, form a cup-shaped body, which may be attached to aninner end wall 26., Thecylindrical wall 24 is so proportioned that itwill nest in an annular notch 27 formed adjacent to the periphery of theinner end wall 26. The inner end wall 26'has a central aperture 28 inwhich there is mounted an anti-friction bearing 29, whereby the innerwall is mounted for rotation on a hollow bear-ing member 30 suitablymounted upon the back wall 31 of the evacuated chamber 6. ,The bearingmember 30 has fixed to it a ,stationary-shaft32, 'a reduced portion 33of which carries an anti-friction bearing 34 that extends into a centralaperture 35 in the outer end wall 23 of the drum 22. A still furtherreduced portion 36 of the shaft 32 is threaded; to receive a knurledthumb knob 37 whereby the unitary structure comprising the end wall 23and the cylindrical wall 24 may readily be mounted upon ,or removed fromthe inner end wall 26. a

The shaft 32 has a central passage 42 formed through out a part of itslength. This passage 42 is formed to receive a pair of insulatedconductors 43 and 44, which may be connected to any suitable powersource. The

conductors 43 and 44 extend through an air tight'seal 41,

into the passage 42 and out of the passage 42 through an aperture 45 tosupply current to a carbon electrode 46. The carbon electrode 46 ismounted on suitable terminal blocks 47 and is clamped in place thereonby clamping plates 48.- The terminal blocks 47 are mounted upon aninsulator 49-which is in turn clamped onto the shaft 32 by suitablycontoured clamp members 50 and 51. Formed in the carbon electrode 46 isa groove or pocket 52 inlwhich there may be placed a pellet '53 ofsilver, which will be Vaporized when the carbon electrode 46 has currentsupplied to it. This vapor will be directed upwardly andthrough the cutouts 25 in the cylindrical wall of the drumand onto the web 10 ofinsulating material passing over the drum.

Inlorder to prevent the vaporized silver from passing out throughapertures or cut cuts 25 in the drum 22 which are not in engagement withthe web of insulating material, a shield is provided which encloses allof the drum 22 except that portion thereof in engagement with the web10. The shield 60 comprises side plates 61 and 62 having inclinedportions 63 and 64 which extend into tangential sliding contact with theouter surface of the cylindrical wall 24 of the drum 22. At their lowerends the side plates 61 and 62 are attached to the bottom 65 of thechamber6 so that the bottom 65 of the chamber 6 also serves ,as' thebottom of the shield 60. In addition to the side plates 61 and 62, theshield 60 includes top plates 66 and 67. Top plate 66 is fixed to theback wall 31 of the chamber 6 and slidingly engages the outer surface ofend wall 26' of the drum 22. Top plate 66 is also formed integrally withor otherwise sealed to the upper ends of inclined portions 63 and 64.

At the rear ,of the chamber 6 the side plates 61 and 62 are "sealed tothe back wall 31 which thus serves as the back wall of the shield 60. Atthe front of the chamber the end wall 23 and cylindrical wall 24 of thedrum 22 to be removed from the evacuated chamber 6 as a unit.

This permits the mounting of drums 22 having diflerent arrangements ofslots or cut outs 25 in them.

If the deposit of silver applied to the web of insulating materialthrough the cut outs in the drum 22 is not heavy v enough to conduct thecurrents to be applied to the circuit for which the Wiring is beingprepared, the vaporizer 17 may be used. This vaporizer may be of thetype known in the art of manufacturing condensers, which will heatzincor other metals such as aluminum or cadmium to a temperaturesufliciently high so that it will vaporize in the evacuated chamber. Itis known that webs of insulating materials such as the web which have apattern of a very light coating of silver applied to them, when passedover a pool of molten zinc at a temperature such that the zinc willvaporize, will cause the zinc to adhere to the web 10 only in thoseareas which have been vaporized with silver. Thus, in the apparatus asshown in Fig. 1, suitable printed wiring will be applied on a very thinlayer of insulating material which may be a paper base on which acoating of lacquer has been applied. In the event that relatively highcurrents are to be carried by the printed wiring, the web 10 with thesilver and zinc deposited upon it in a pattern conforming to the patternof the drum 22 may have a further and heavier layer of metal applied onthe pattern by electrolytic deposition of suitable metals on thepattern.

In practising the invention a pellet 53 of silver is placed in thegroove 52 of the electrode 46 and then the cupshaped body comprising theouter end wall 23 and cylindrical wall 24 is mounted on the inner endwall 26. The unitary structure of the outer end wall 23 and cylindricalwall 24 is held in place by threading the thumb nut 37 onto the portion36 of the shaft 32. If it is assumed that a large number of printedcircuits such as that illustrated at 76 (Fig. 3) are to be printed, thecut outs 25 in the cylindrical wall 24- of the drum 22 will conform tothe pattern 70. It will be noted from an inspection of Fig. 3 that thecircuit paths are elongated and intersect. In order to product suchcircuit paths, the drum is provided with elongated (see Fig. 2)intersecting slots extending through the periphery thereof. Drums 22having different patterns may be substituted for the one illustrated toprovide circuit arrangements of any desired design.

After the drum '22 has been assembled and locked in place by the thumbnut 37, a supply of zinc having been put in the vaporizer 17, a supplyof insulating material 8 in web form may be positioned on the arbor 7.The insulating material preferably comprises the web 10 made of paper onwhich there has been applied a coating of lacquer that serves to sealany porosity in the paper. The web It} from the supply 3 is fed underguide roller 9 and up over inclined portion 63 of side plate 61 intoengagement with a substantial portion of cylindrical wall 24 of drum 22.From the drum 22 the web 10 is directed over inclined portion 64 of sideplate 62, under guide roller 12, over guide rollers 13 and 14 and underguide roller.

15 to take up arbor 16. In passing over guide rollers 13 and 14 the webhas a portion of it exposed to zinc vaporizer 17.

After the web has thus been placed in position the front wall 68 issealed to the side walls, the top and bottom walls and the top plate 67of shield 60 is simultaneously slid into sealing engagement with theupper edges of inclined portions 63; and 64-. The chamber 6 is thussealed and the shield 66' around the drum 22 is closed whereupon thechamber 6 is evacuated. As soon as chamber 6 is suitably evacuated,power is supplied to the vaporizer 17 through cable 18 and power issupplied to electrode 46 through conductors 43 and 44. As soon as thepower supplied is connected to the vaporizer 17 and to the electrode 46,take up arbor 16 is actuated so that the web 10 will not be charredwhile the vaporizer 17 and electrode 46 are beating up to the pointwhere they will vaporize the metals in them. Thus, the first portion ofthe web wound on take up arbor 16 will not have metal deposited on itbut as soon as vapors are generated the metals will deposit on the web10. The web 10 will turn the drum 22 and the pattern of cut outs 25 inthe cylindrical wall 24 of drum 22 will control the pattern 70 of metalsto be deposited. v

Cir

If a pattern of silver is sufliciently heavy the zinc vaporizer 17 neednot be operated. Furthermore, if the pattern of silver and zinc is notheavy enough to carry the currents to be used in the circuit for whichthe wiring is being prepared, an additional metal coating may beelectroplated on the zinc.

Although a specific apparatus for practising the invention has beendescribed in detail, it will be understood that numerous modificationsmay be made without departing from the invention.

What is claimed is:

1. An apparatus for producing printed wiring having transverselyextending metallic circuit paths comprising an evacuated chamber havingtherein an arbor for supporting a supply of insulating material in webform, a take-up arbor for withdrawing said web of insulating materialfrom the supply thereof, a rotative drum having elongated slots in itscylindrical wall to define a predetermined pattern of elongated slots insaid cylindrical wall, said pattern of elongated slots extendingcircumferentially and axially along the peripheral surface of the drum,means for guiding a web of insulating material from the supply arbor tothe take-up arbor over the drum for engaging and rotating the drum, ametal vaporizer within said drum for directing vaporized metal throughsaid elongated slots onto the surface of said web to form metalliccircuit patterns extending longitudinally and transversely of the web,and a second vaporizer for vaporizing another metal adjacent to the pathof said web for applying a coating of said second metal on thepreviously applied metallic pattern on the web.

2. An apparatus for producing printed wiring having elongatedintersecting circuit paths comprising an evacuated chamber havingtherein an arbor for supporting a supply of insulating material in Webform, a take-up arbor for withdrawing said web of insulating materialfrom the supply thereof, a rotative, two-piece drum, a stationary shaftfor supporting said drum, one piece of said drum comprising an innerwall member freely rotatable about said shaft and having an annularnotch adjacent to its periphery and the other piece of said drumcomprising an integrally formed outer wall freely rotatable about saidshaft and a cylindrical wall, said cylindrical wall being provided withpattern-defining elongated intersecting slots and being formed to fitthe annular notch on the periphery of the inner wall member, means foradvancing the insulating material over the cylindrical wall to rotatethe drum to successively present the intersecting slots to successiveareas of the advancing insulating material, and a metal vaporizermounted on said stationary shaft and within said drum for directingmetallic vapor through said elongated slots to form elongatedintersecting deposits on the web.

3. An apparatus for producing printed wiring having intersecting circuitpaths, comprising an evacuated chamber having a hollow bearing membersecured to a wall of said chamber, a rotative drum mounted on saidbearing member and having a pattern of elongated intersecting slotsextending through the periphery thereof, a shield mounted on the wallsof said chamber and about the drum to longitudinally engage the drumalong two spaced lines to expose a predetermined peripheral area to saidevacuated chamber, a bracket mounted on said bearing at a pointcentrally located with respect to the ends of the drum for supportingmetal to be vaporized, a heater mounted on said bracket for vaporizingthe metal, conductors connected to said heater and extending throughsaid hollow member for supplying current to said heater, and means foradvancing and guiding a web into contact with the predetermined exposedarea of the drum to thereby rotate the drum whereby a pattern ofintersecting paths of metal is deposited on the web in conformance withthe pattern of slots advanced through the predetermined exposed area bythe rotating drum.

4. An apparatus for producing printed wiring having intersecting circuitpaths, comprising an evacuated chamber, an arbor rotatably mounted insaid chamber for supporting a supply of insulating material in web form,a take-up arbor mounted in said chamber for withdrawing said web ofinsulating material from the supply thereof, a rotative drum mounted insaid chamber having slots in its cylindrical wall to definepredetermined patterns of intersecting openings in said cylindricalwall, each pattern of openings including circumferentially and axiallyextending intersecting slots, means for guiding a web of insulatingmaterial from the supply arbor to the take-up arbor over a predeterminedportion of the drum for engaging and rotating the drum, a metalvaporizer within said drum for directing vaporized metal through saidslots onto the surface of said web, and means to shield all of said drumexcept the predetermined portion engaged by the web from the remainderof the chamber for presenting each succeeding pattern of intersectingopenings to successive portions of the advancing web whereby metal isdeposited on the web to form intersecting circuit paths.

References Cited in the file of this patent UNITED STATES PATENTS746,786 Burdick Dec. 15, 1903 1,551,850 Schmidmer et a1. Sept. 1, 19251,701,568 Hubl Feb. 12, 1929 2,103,623 Kott Dec. 28, 1937 2,382,432McManus et al. Aug. 14, 1945 2,426,494 Evans Aug. 26, 1947 2,702,760Barth Feb. 22, 195-5 2,750,921 Purdy June 19, 1956 FOREIGN PATENTS767,381 Germany July 28, 1952 760,543 Germany June 8, 1953 692,614 GreatBritain June 10, 1953

